net/ipv6/ip6_fib.c

   1 /*
   2  *      Linux INET6 implementation
   3  *      Forwarding Information Database
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 /*
  15  *      Changes:
  16  *      Yuji SEKIYA @USAGI:     Support default route on router node;
  17  *                              remove ip6_null_entry from the top of
  18  *                              routing table.
  19  *      Ville Nuorvala:         Fixed routing subtrees.
  20  */
  21 #include <linux/errno.h>
  22 #include <linux/types.h>
  23 #include <linux/net.h>
  24 #include <linux/route.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/in6.h>
  27 #include <linux/init.h>
  28 #include <linux/list.h>
  29
  30 #ifdef  CONFIG_PROC_FS
  31 #include <linux/proc_fs.h>
  32 #endif
  33
  34 #include <net/ipv6.h>
  35 #include <net/ndisc.h>
  36 #include <net/addrconf.h>
  37
  38 #include <net/ip6_fib.h>
  39 #include <net/ip6_route.h>
  40
  41 #define RT6_DEBUG 2
  42
  43 #if RT6_DEBUG >= 3
  44 #define RT6_TRACE(x...) printk(KERN_DEBUG x)
  45 #else
  46 #define RT6_TRACE(x...) do { ; } while (0)
  47 #endif
  48
  49 static struct kmem_cache * fib6_node_kmem __read_mostly;
  50
  51 enum fib_walk_state_t
  52 {
  53 #ifdef CONFIG_IPV6_SUBTREES
  54         FWS_S,
  55 #endif
  56         FWS_L,
  57         FWS_R,
  58         FWS_C,
  59         FWS_U
  60 };
  61
  62 struct fib6_cleaner_t
  63 {
  64         struct fib6_walker_t w;
  65         struct net *net;
  66         int (*func)(struct rt6_info *, void *arg);
  67         void *arg;
  68 };
  69
  70 static DEFINE_RWLOCK(fib6_walker_lock);
  71
  72 #ifdef CONFIG_IPV6_SUBTREES
  73 #define FWS_INIT FWS_S
  74 #else
  75 #define FWS_INIT FWS_L
  76 #endif
  77
  78 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
  79                               struct rt6_info *rt);
  80 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
  81 static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
  82 static int fib6_walk(struct fib6_walker_t *w);
  83 static int fib6_walk_continue(struct fib6_walker_t *w);
  84
  85 /*
  86  *      A routing update causes an increase of the serial number on the
  87  *      affected subtree. This allows for cached routes to be asynchronously
  88  *      tested when modifications are made to the destination cache as a
  89  *      result of redirects, path MTU changes, etc.
  90  */
  91
  92 static __u32 rt_sernum;
  93
  94 static void fib6_gc_timer_cb(unsigned long arg);
  95
  96 static struct fib6_walker_t fib6_walker_list = {
  97         .prev   = &fib6_walker_list,
  98         .next   = &fib6_walker_list,
  99 };
 100
 101 #define FOR_WALKERS(w) for ((w)=fib6_walker_list.next; (w) != &fib6_walker_list; (w)=(w)->next)
 102
 103 static inline void fib6_walker_link(struct fib6_walker_t *w)
 104 {
 105         write_lock_bh(&fib6_walker_lock);
 106         w->next = fib6_walker_list.next;
 107         w->prev = &fib6_walker_list;
 108         w->next->prev = w;
 109         w->prev->next = w;
 110         write_unlock_bh(&fib6_walker_lock);
 111 }
 112
 113 static inline void fib6_walker_unlink(struct fib6_walker_t *w)
 114 {
 115         write_lock_bh(&fib6_walker_lock);
 116         w->next->prev = w->prev;
 117         w->prev->next = w->next;
 118         w->prev = w->next = w;
 119         write_unlock_bh(&fib6_walker_lock);
 120 }
 121 static __inline__ u32 fib6_new_sernum(void)
 122 {
 123         u32 n = ++rt_sernum;
 124         if ((__s32)n <= 0)
 125                 rt_sernum = n = 1;
 126         return n;
 127 }
 128
 129 /*
 130  *      Auxiliary address test functions for the radix tree.
 131  *
 132  *      These assume a 32bit processor (although it will work on
 133  *      64bit processors)
 134  */
 135
 136 /*
 137  *      test bit
 138  */
 139
 140 static __inline__ __be32 addr_bit_set(void *token, int fn_bit)
 141 {
 142         __be32 *addr = token;
 143
 144         return htonl(1 << ((~fn_bit)&0x1F)) & addr[fn_bit>>5];
 145 }
 146
 147 static __inline__ struct fib6_node * node_alloc(void)
 148 {
 149         struct fib6_node *fn;
 150
 151         fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
 152
 153         return fn;
 154 }
 155
 156 static __inline__ void node_free(struct fib6_node * fn)
 157 {
 158         kmem_cache_free(fib6_node_kmem, fn);
 159 }
 160
 161 static __inline__ void rt6_release(struct rt6_info *rt)
 162 {
 163         if (atomic_dec_and_test(&rt->rt6i_ref))
 164                 dst_free(&rt->u.dst);
 165 }
 166
 167 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 168 #define FIB_TABLE_HASHSZ 256
 169 #else
 170 #define FIB_TABLE_HASHSZ 1
 171 #endif
 172
 173 static void fib6_link_table(struct net *net, struct fib6_table *tb)
 174 {
 175         unsigned int h;
 176
 177         /*
 178          * Initialize table lock at a single place to give lockdep a key,
 179          * tables aren't visible prior to being linked to the list.
 180          */
 181         rwlock_init(&tb->tb6_lock);
 182
 183         h = tb->tb6_id & (FIB_TABLE_HASHSZ - 1);
 184
 185         /*
 186          * No protection necessary, this is the only list mutatation
 187          * operation, tables never disappear once they exist.
 188          */
 189         hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
 190 }
 191
 192 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 193
 194 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
 195 {
 196         struct fib6_table *table;
 197
 198         table = kzalloc(sizeof(*table), GFP_ATOMIC);
 199         if (table != NULL) {
 200                 table->tb6_id = id;
 201                 table->tb6_root.leaf = net->ipv6.ip6_null_entry;
 202                 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
 203         }
 204
 205         return table;
 206 }
 207
 208 struct fib6_table *fib6_new_table(struct net *net, u32 id)
 209 {
 210         struct fib6_table *tb;
 211
 212         if (id == 0)
 213                 id = RT6_TABLE_MAIN;
 214         tb = fib6_get_table(net, id);
 215         if (tb)
 216                 return tb;
 217
 218         tb = fib6_alloc_table(net, id);
 219         if (tb != NULL)
 220                 fib6_link_table(net, tb);
 221
 222         return tb;
 223 }
 224
 225 struct fib6_table *fib6_get_table(struct net *net, u32 id)
 226 {
 227         struct fib6_table *tb;
 228         struct hlist_head *head;
 229         struct hlist_node *node;
 230         unsigned int h;
 231
 232         if (id == 0)
 233                 id = RT6_TABLE_MAIN;
 234         h = id & (FIB_TABLE_HASHSZ - 1);
 235         rcu_read_lock();
 236         head = &net->ipv6.fib_table_hash[h];
 237         hlist_for_each_entry_rcu(tb, node, head, tb6_hlist) {
 238                 if (tb->tb6_id == id) {
 239                         rcu_read_unlock();
 240                         return tb;
 241                 }
 242         }
 243         rcu_read_unlock();
 244
 245         return NULL;
 246 }
 247
 248 static void fib6_tables_init(struct net *net)
 249 {
 250         fib6_link_table(net, net->ipv6.fib6_main_tbl);
 251         fib6_link_table(net, net->ipv6.fib6_local_tbl);
 252 }
 253 #else
 254
 255 struct fib6_table *fib6_new_table(struct net *net, u32 id)
 256 {
 257         return fib6_get_table(net, id);
 258 }
 259
 260 struct fib6_table *fib6_get_table(struct net *net, u32 id)
 261 {
 262           return net->ipv6.fib6_main_tbl;
 263 }
 264
 265 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi *fl,
 266                                    int flags, pol_lookup_t lookup)
 267 {
 268         return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl, flags);
 269 }
 270
 271 static void fib6_tables_init(struct net *net)
 272 {
 273         fib6_link_table(net, net->ipv6.fib6_main_tbl);
 274 }
 275
 276 #endif
 277
 278 static int fib6_dump_node(struct fib6_walker_t *w)
 279 {
 280         int res;
 281         struct rt6_info *rt;
 282
 283         for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) {
 284                 res = rt6_dump_route(rt, w->args);
 285                 if (res < 0) {
 286                         /* Frame is full, suspend walking */
 287                         w->leaf = rt;
 288                         return 1;
 289                 }
 290                 BUG_TRAP(res!=0);
 291         }
 292         w->leaf = NULL;
 293         return 0;
 294 }
 295
 296 static void fib6_dump_end(struct netlink_callback *cb)
 297 {
 298         struct fib6_walker_t *w = (void*)cb->args[2];
 299
 300         if (w) {
 301                 cb->args[2] = 0;
 302                 kfree(w);
 303         }
 304         cb->done = (void*)cb->args[3];
 305         cb->args[1] = 3;
 306 }
 307
 308 static int fib6_dump_done(struct netlink_callback *cb)
 309 {
 310         fib6_dump_end(cb);
 311         return cb->done ? cb->done(cb) : 0;
 312 }
 313
 314 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
 315                            struct netlink_callback *cb)
 316 {
 317         struct fib6_walker_t *w;
 318         int res;
 319
 320         w = (void *)cb->args[2];
 321         w->root = &table->tb6_root;
 322
 323         if (cb->args[4] == 0) {
 324                 read_lock_bh(&table->tb6_lock);
 325                 res = fib6_walk(w);
 326                 read_unlock_bh(&table->tb6_lock);
 327                 if (res > 0)
 328                         cb->args[4] = 1;
 329         } else {
 330                 read_lock_bh(&table->tb6_lock);
 331                 res = fib6_walk_continue(w);
 332                 read_unlock_bh(&table->tb6_lock);
 333                 if (res != 0) {
 334                         if (res < 0)
 335                                 fib6_walker_unlink(w);
 336                         goto end;
 337                 }
 338                 fib6_walker_unlink(w);
 339                 cb->args[4] = 0;
 340         }
 341 end:
 342         return res;
 343 }
 344
 345 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
 346 {
 347         struct net *net = sock_net(skb->sk);
 348         unsigned int h, s_h;
 349         unsigned int e = 0, s_e;
 350         struct rt6_rtnl_dump_arg arg;
 351         struct fib6_walker_t *w;
 352         struct fib6_table *tb;
 353         struct hlist_node *node;
 354         struct hlist_head *head;
 355         int res = 0;
 356
 357         s_h = cb->args[0];
 358         s_e = cb->args[1];
 359
 360         w = (void *)cb->args[2];
 361         if (w == NULL) {
 362                 /* New dump:
 363                  *
 364                  * 1. hook callback destructor.
 365                  */
 366                 cb->args[3] = (long)cb->done;
 367                 cb->done = fib6_dump_done;
 368
 369                 /*
 370                  * 2. allocate and initialize walker.
 371                  */
 372                 w = kzalloc(sizeof(*w), GFP_ATOMIC);
 373                 if (w == NULL)
 374                         return -ENOMEM;
 375                 w->func = fib6_dump_node;
 376                 cb->args[2] = (long)w;
 377         }
 378
 379         arg.skb = skb;
 380         arg.cb = cb;
 381         w->args = &arg;
 382
 383         for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
 384                 e = 0;
 385                 head = &net->ipv6.fib_table_hash[h];
 386                 hlist_for_each_entry(tb, node, head, tb6_hlist) {
 387                         if (e < s_e)
 388                                 goto next;
 389                         res = fib6_dump_table(tb, skb, cb);
 390                         if (res != 0)
 391                                 goto out;
 392 next:
 393                         e++;
 394                 }
 395         }
 396 out:
 397         cb->args[1] = e;
 398         cb->args[0] = h;
 399
 400         res = res < 0 ? res : skb->len;
 401         if (res <= 0)
 402                 fib6_dump_end(cb);
 403         return res;
 404 }
 405
 406 /*
 407  *      Routing Table
 408  *
 409  *      return the appropriate node for a routing tree "add" operation
 410  *      by either creating and inserting or by returning an existing
 411  *      node.
 412  */
 413
 414 static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr,
 415                                      int addrlen, int plen,
 416                                      int offset)
 417 {
 418         struct fib6_node *fn, *in, *ln;
 419         struct fib6_node *pn = NULL;
 420         struct rt6key *key;
 421         int     bit;
 422         __be32  dir = 0;
 423         __u32   sernum = fib6_new_sernum();
 424
 425         RT6_TRACE("fib6_add_1\n");
 426
 427         /* insert node in tree */
 428
 429         fn = root;
 430
 431         do {
 432                 key = (struct rt6key *)((u8 *)fn->leaf + offset);
 433
 434                 /*
 435                  *      Prefix match
 436                  */
 437                 if (plen < fn->fn_bit ||
 438                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
 439                         goto insert_above;
 440
 441                 /*
 442                  *      Exact match ?
 443                  */
 444
 445                 if (plen == fn->fn_bit) {
 446                         /* clean up an intermediate node */
 447                         if ((fn->fn_flags & RTN_RTINFO) == 0) {
 448                                 rt6_release(fn->leaf);
 449                                 fn->leaf = NULL;
 450                         }
 451
 452                         fn->fn_sernum = sernum;
 453
 454                         return fn;
 455                 }
 456
 457                 /*
 458                  *      We have more bits to go
 459                  */
 460
 461                 /* Try to walk down on tree. */
 462                 fn->fn_sernum = sernum;
 463                 dir = addr_bit_set(addr, fn->fn_bit);
 464                 pn = fn;
 465                 fn = dir ? fn->right: fn->left;
 466         } while (fn);
 467
 468         /*
 469          *      We walked to the bottom of tree.
 470          *      Create new leaf node without children.
 471          */
 472
 473         ln = node_alloc();
 474
 475         if (ln == NULL)
 476                 return NULL;
 477         ln->fn_bit = plen;
 478
 479         ln->parent = pn;
 480         ln->fn_sernum = sernum;
 481
 482         if (dir)
 483                 pn->right = ln;
 484         else
 485                 pn->left  = ln;
 486
 487         return ln;
 488
 489
 490 insert_above:
 491         /*
 492          * split since we don't have a common prefix anymore or
 493          * we have a less significant route.
 494          * we've to insert an intermediate node on the list
 495          * this new node will point to the one we need to create
 496          * and the current
 497          */
 498
 499         pn = fn->parent;
 500
 501         /* find 1st bit in difference between the 2 addrs.
 502
 503            See comment in __ipv6_addr_diff: bit may be an invalid value,
 504            but if it is >= plen, the value is ignored in any case.
 505          */
 506
 507         bit = __ipv6_addr_diff(addr, &key->addr, addrlen);
 508
 509         /*
 510          *              (intermediate)[in]
 511          *                /        \
 512          *      (new leaf node)[ln] (old node)[fn]
 513          */
 514         if (plen > bit) {
 515                 in = node_alloc();
 516                 ln = node_alloc();
 517
 518                 if (in == NULL || ln == NULL) {
 519                         if (in)
 520                                 node_free(in);
 521                         if (ln)
 522                                 node_free(ln);
 523                         return NULL;
 524                 }
 525
 526                 /*
 527                  * new intermediate node.
 528                  * RTN_RTINFO will
 529                  * be off since that an address that chooses one of
 530                  * the branches would not match less specific routes
 531                  * in the other branch
 532                  */
 533
 534                 in->fn_bit = bit;
 535
 536                 in->parent = pn;
 537                 in->leaf = fn->leaf;
 538                 atomic_inc(&in->leaf->rt6i_ref);
 539
 540                 in->fn_sernum = sernum;
 541
 542                 /* update parent pointer */
 543                 if (dir)
 544                         pn->right = in;
 545                 else
 546                         pn->left  = in;
 547
 548                 ln->fn_bit = plen;
 549
 550                 ln->parent = in;
 551                 fn->parent = in;
 552
 553                 ln->fn_sernum = sernum;
 554
 555                 if (addr_bit_set(addr, bit)) {
 556                         in->right = ln;
 557                         in->left  = fn;
 558                 } else {
 559                         in->left  = ln;
 560                         in->right = fn;
 561                 }
 562         } else { /* plen <= bit */
 563
 564                 /*
 565                  *              (new leaf node)[ln]
 566                  *                /        \
 567                  *           (old node)[fn] NULL
 568                  */
 569
 570                 ln = node_alloc();
 571
 572                 if (ln == NULL)
 573                         return NULL;
 574
 575                 ln->fn_bit = plen;
 576
 577                 ln->parent = pn;
 578
 579                 ln->fn_sernum = sernum;
 580
 581                 if (dir)
 582                         pn->right = ln;
 583                 else
 584                         pn->left  = ln;
 585
 586                 if (addr_bit_set(&key->addr, plen))
 587                         ln->right = fn;
 588                 else
 589                         ln->left  = fn;
 590
 591                 fn->parent = ln;
 592         }
 593         return ln;
 594 }
 595
 596 /*
 597  *      Insert routing information in a node.
 598  */
 599
 600 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
 601                             struct nl_info *info)
 602 {
 603         struct rt6_info *iter = NULL;
 604         struct rt6_info **ins;
 605
 606         ins = &fn->leaf;
 607
 608         for (iter = fn->leaf; iter; iter=iter->u.dst.rt6_next) {
 609                 /*
 610                  *      Search for duplicates
 611                  */
 612
 613                 if (iter->rt6i_metric == rt->rt6i_metric) {
 614                         /*
 615                          *      Same priority level
 616                          */
 617
 618                         if (iter->rt6i_dev == rt->rt6i_dev &&
 619                             iter->rt6i_idev == rt->rt6i_idev &&
 620                             ipv6_addr_equal(&iter->rt6i_gateway,
 621                                             &rt->rt6i_gateway)) {
 622                                 if (!(iter->rt6i_flags&RTF_EXPIRES))
 623                                         return -EEXIST;
 624                                 iter->rt6i_expires = rt->rt6i_expires;
 625                                 if (!(rt->rt6i_flags&RTF_EXPIRES)) {
 626                                         iter->rt6i_flags &= ~RTF_EXPIRES;
 627                                         iter->rt6i_expires = 0;
 628                                 }
 629                                 return -EEXIST;
 630                         }
 631                 }
 632
 633                 if (iter->rt6i_metric > rt->rt6i_metric)
 634                         break;
 635
 636                 ins = &iter->u.dst.rt6_next;
 637         }
 638
 639         /* Reset round-robin state, if necessary */
 640         if (ins == &fn->leaf)
 641                 fn->rr_ptr = NULL;
 642
 643         /*
 644          *      insert node
 645          */
 646
 647         rt->u.dst.rt6_next = iter;
 648         *ins = rt;
 649         rt->rt6i_node = fn;
 650         atomic_inc(&rt->rt6i_ref);
 651         inet6_rt_notify(RTM_NEWROUTE, rt, info);
 652         info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
 653
 654         if ((fn->fn_flags & RTN_RTINFO) == 0) {
 655                 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
 656                 fn->fn_flags |= RTN_RTINFO;
 657         }
 658
 659         return 0;
 660 }
 661
 662 static __inline__ void fib6_start_gc(struct net *net, struct rt6_info *rt)
 663 {
 664         if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
 665             (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE)))
 666                 mod_timer(&net->ipv6.ip6_fib_timer,
 667                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
 668 }
 669
 670 void fib6_force_start_gc(struct net *net)
 671 {
 672         if (!timer_pending(&net->ipv6.ip6_fib_timer))
 673                 mod_timer(&net->ipv6.ip6_fib_timer,
 674                           jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
 675 }
 676
 677 /*
 678  *      Add routing information to the routing tree.
 679  *      <destination addr>/<source addr>
 680  *      with source addr info in sub-trees
 681  */
 682
 683 int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info)
 684 {
 685         struct fib6_node *fn, *pn = NULL;
 686         int err = -ENOMEM;
 687
 688         fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
 689                         rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst));
 690
 691         if (fn == NULL)
 692                 goto out;
 693
 694         pn = fn;
 695
 696 #ifdef CONFIG_IPV6_SUBTREES
 697         if (rt->rt6i_src.plen) {
 698                 struct fib6_node *sn;
 699
 700                 if (fn->subtree == NULL) {
 701                         struct fib6_node *sfn;
 702
 703                         /*
 704                          * Create subtree.
 705                          *
 706                          *              fn[main tree]
 707                          *              |
 708                          *              sfn[subtree root]
 709                          *                 \
 710                          *                  sn[new leaf node]
 711                          */
 712
 713                         /* Create subtree root node */
 714                         sfn = node_alloc();
 715                         if (sfn == NULL)
 716                                 goto st_failure;
 717
 718                         sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
 719                         atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
 720                         sfn->fn_flags = RTN_ROOT;
 721                         sfn->fn_sernum = fib6_new_sernum();
 722
 723                         /* Now add the first leaf node to new subtree */
 724
 725                         sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
 726                                         sizeof(struct in6_addr), rt->rt6i_src.plen,
 727                                         offsetof(struct rt6_info, rt6i_src));
 728
 729                         if (sn == NULL) {
 730                                 /* If it is failed, discard just allocated
 731                                    root, and then (in st_failure) stale node
 732                                    in main tree.
 733                                  */
 734                                 node_free(sfn);
 735                                 goto st_failure;
 736                         }
 737
 738                         /* Now link new subtree to main tree */
 739                         sfn->parent = fn;
 740                         fn->subtree = sfn;
 741                 } else {
 742                         sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
 743                                         sizeof(struct in6_addr), rt->rt6i_src.plen,
 744                                         offsetof(struct rt6_info, rt6i_src));
 745
 746                         if (sn == NULL)
 747                                 goto st_failure;
 748                 }
 749
 750                 if (fn->leaf == NULL) {
 751                         fn->leaf = rt;
 752                         atomic_inc(&rt->rt6i_ref);
 753                 }
 754                 fn = sn;
 755         }
 756 #endif
 757
 758         err = fib6_add_rt2node(fn, rt, info);
 759
 760         if (err == 0) {
 761                 fib6_start_gc(info->nl_net, rt);
 762                 if (!(rt->rt6i_flags&RTF_CACHE))
 763                         fib6_prune_clones(info->nl_net, pn, rt);
 764         }
 765
 766 out:
 767         if (err) {
 768 #ifdef CONFIG_IPV6_SUBTREES
 769                 /*
 770                  * If fib6_add_1 has cleared the old leaf pointer in the
 771                  * super-tree leaf node we have to find a new one for it.
 772                  */
 773                 if (pn != fn && pn->leaf == rt) {
 774                         pn->leaf = NULL;
 775                         atomic_dec(&rt->rt6i_ref);
 776                 }
 777                 if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
 778                         pn->leaf = fib6_find_prefix(info->nl_net, pn);
 779 #if RT6_DEBUG >= 2
 780                         if (!pn->leaf) {
 781                                 BUG_TRAP(pn->leaf != NULL);
 782                                 pn->leaf = info->nl_net->ipv6.ip6_null_entry;
 783                         }
 784 #endif
 785                         atomic_inc(&pn->leaf->rt6i_ref);
 786                 }
 787 #endif
 788                 dst_free(&rt->u.dst);
 789         }
 790         return err;
 791
 792 #ifdef CONFIG_IPV6_SUBTREES
 793         /* Subtree creation failed, probably main tree node
 794            is orphan. If it is, shoot it.
 795          */
 796 st_failure:
 797         if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
 798                 fib6_repair_tree(info->nl_net, fn);
 799         dst_free(&rt->u.dst);
 800         return err;
 801 #endif
 802 }
 803
 804 /*
 805  *      Routing tree lookup
 806  *
 807  */
 808
 809 struct lookup_args {
 810         int             offset;         /* key offset on rt6_info       */
 811         struct in6_addr *addr;          /* search key                   */
 812 };
 813
 814 static struct fib6_node * fib6_lookup_1(struct fib6_node *root,
 815                                         struct lookup_args *args)
 816 {
 817         struct fib6_node *fn;
 818         __be32 dir;
 819
 820         if (unlikely(args->offset == 0))
 821                 return NULL;
 822
 823         /*
 824          *      Descend on a tree
 825          */
 826
 827         fn = root;
 828
 829         for (;;) {
 830                 struct fib6_node *next;
 831
 832                 dir = addr_bit_set(args->addr, fn->fn_bit);
 833
 834                 next = dir ? fn->right : fn->left;
 835
 836                 if (next) {
 837                         fn = next;
 838                         continue;
 839                 }
 840
 841                 break;
 842         }
 843
 844         while(fn) {
 845                 if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
 846                         struct rt6key *key;
 847
 848                         key = (struct rt6key *) ((u8 *) fn->leaf +
 849                                                  args->offset);
 850
 851                         if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
 852 #ifdef CONFIG_IPV6_SUBTREES
 853                                 if (fn->subtree)
 854                                         fn = fib6_lookup_1(fn->subtree, args + 1);
 855 #endif
 856                                 if (!fn || fn->fn_flags & RTN_RTINFO)
 857                                         return fn;
 858                         }
 859                 }
 860
 861                 if (fn->fn_flags & RTN_ROOT)
 862                         break;
 863
 864                 fn = fn->parent;
 865         }
 866
 867         return NULL;
 868 }
 869
 870 struct fib6_node * fib6_lookup(struct fib6_node *root, struct in6_addr *daddr,
 871                                struct in6_addr *saddr)
 872 {
 873         struct fib6_node *fn;
 874         struct lookup_args args[] = {
 875                 {
 876                         .offset = offsetof(struct rt6_info, rt6i_dst),
 877                         .addr = daddr,
 878                 },
 879 #ifdef CONFIG_IPV6_SUBTREES
 880                 {
 881                         .offset = offsetof(struct rt6_info, rt6i_src),
 882                         .addr = saddr,
 883                 },
 884 #endif
 885                 {
 886                         .offset = 0,    /* sentinel */
 887                 }
 888         };
 889
 890         fn = fib6_lookup_1(root, daddr ? args : args + 1);
 891
 892         if (fn == NULL || fn->fn_flags & RTN_TL_ROOT)
 893                 fn = root;
 894
 895         return fn;
 896 }
 897
 898 /*
 899  *      Get node with specified destination prefix (and source prefix,
 900  *      if subtrees are used)
 901  */
 902
 903
 904 static struct fib6_node * fib6_locate_1(struct fib6_node *root,
 905                                         struct in6_addr *addr,
 906                                         int plen, int offset)
 907 {
 908         struct fib6_node *fn;
 909
 910         for (fn = root; fn ; ) {
 911                 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
 912
 913                 /*
 914                  *      Prefix match
 915                  */
 916                 if (plen < fn->fn_bit ||
 917                     !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
 918                         return NULL;
 919
 920                 if (plen == fn->fn_bit)
 921                         return fn;
 922
 923                 /*
 924                  *      We have more bits to go
 925                  */
 926                 if (addr_bit_set(addr, fn->fn_bit))
 927                         fn = fn->right;
 928                 else
 929                         fn = fn->left;
 930         }
 931         return NULL;
 932 }
 933
 934 struct fib6_node * fib6_locate(struct fib6_node *root,
 935                                struct in6_addr *daddr, int dst_len,
 936                                struct in6_addr *saddr, int src_len)
 937 {
 938         struct fib6_node *fn;
 939
 940         fn = fib6_locate_1(root, daddr, dst_len,
 941                            offsetof(struct rt6_info, rt6i_dst));
 942
 943 #ifdef CONFIG_IPV6_SUBTREES
 944         if (src_len) {
 945                 BUG_TRAP(saddr!=NULL);
 946                 if (fn && fn->subtree)
 947                         fn = fib6_locate_1(fn->subtree, saddr, src_len,
 948                                            offsetof(struct rt6_info, rt6i_src));
 949         }
 950 #endif
 951
 952         if (fn && fn->fn_flags&RTN_RTINFO)
 953                 return fn;
 954
 955         return NULL;
 956 }
 957
 958
 959 /*
 960  *      Deletion
 961  *
 962  */
 963
 964 static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
 965 {
 966         if (fn->fn_flags&RTN_ROOT)
 967                 return net->ipv6.ip6_null_entry;
 968
 969         while(fn) {
 970                 if(fn->left)
 971                         return fn->left->leaf;
 972
 973                 if(fn->right)
 974                         return fn->right->leaf;
 975
 976                 fn = FIB6_SUBTREE(fn);
 977         }
 978         return NULL;
 979 }
 980
 981 /*
 982  *      Called to trim the tree of intermediate nodes when possible. "fn"
 983  *      is the node we want to try and remove.
 984  */
 985
 986 static struct fib6_node *fib6_repair_tree(struct net *net,
 987                                            struct fib6_node *fn)
 988 {
 989         int children;
 990         int nstate;
 991         struct fib6_node *child, *pn;
 992         struct fib6_walker_t *w;
 993         int iter = 0;
 994
 995         for (;;) {
 996                 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
 997                 iter++;
 998
 999                 BUG_TRAP(!(fn->fn_flags&RTN_RTINFO));
1000                 BUG_TRAP(!(fn->fn_flags&RTN_TL_ROOT));
1001                 BUG_TRAP(fn->leaf==NULL);
1002
1003                 children = 0;
1004                 child = NULL;
1005                 if (fn->right) child = fn->right, children |= 1;
1006                 if (fn->left) child = fn->left, children |= 2;
1007
1008                 if (children == 3 || FIB6_SUBTREE(fn)
1009 #ifdef CONFIG_IPV6_SUBTREES
1010                     /* Subtree root (i.e. fn) may have one child */
1011                     || (children && fn->fn_flags&RTN_ROOT)
1012 #endif
1013                     ) {
1014                         fn->leaf = fib6_find_prefix(net, fn);
1015 #if RT6_DEBUG >= 2
1016                         if (fn->leaf==NULL) {
1017                                 BUG_TRAP(fn->leaf);
1018                                 fn->leaf = net->ipv6.ip6_null_entry;
1019                         }
1020 #endif
1021                         atomic_inc(&fn->leaf->rt6i_ref);
1022                         return fn->parent;
1023                 }
1024
1025                 pn = fn->parent;
1026 #ifdef CONFIG_IPV6_SUBTREES
1027                 if (FIB6_SUBTREE(pn) == fn) {
1028                         BUG_TRAP(fn->fn_flags&RTN_ROOT);
1029                         FIB6_SUBTREE(pn) = NULL;
1030                         nstate = FWS_L;
1031                 } else {
1032                         BUG_TRAP(!(fn->fn_flags&RTN_ROOT));
1033 #endif
1034                         if (pn->right == fn) pn->right = child;
1035                         else if (pn->left == fn) pn->left = child;
1036 #if RT6_DEBUG >= 2
1037                         else BUG_TRAP(0);
1038 #endif
1039                         if (child)
1040                                 child->parent = pn;
1041                         nstate = FWS_R;
1042 #ifdef CONFIG_IPV6_SUBTREES
1043                 }
1044 #endif
1045
1046                 read_lock(&fib6_walker_lock);
1047                 FOR_WALKERS(w) {
1048                         if (child == NULL) {
1049                                 if (w->root == fn) {
1050                                         w->root = w->node = NULL;
1051                                         RT6_TRACE("W %p adjusted by delroot 1\n", w);
1052                                 } else if (w->node == fn) {
1053                                         RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1054                                         w->node = pn;
1055                                         w->state = nstate;
1056                                 }
1057                         } else {
1058                                 if (w->root == fn) {
1059                                         w->root = child;
1060                                         RT6_TRACE("W %p adjusted by delroot 2\n", w);
1061                                 }
1062                                 if (w->node == fn) {
1063                                         w->node = child;
1064                                         if (children&2) {
1065                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1066                                                 w->state = w->state>=FWS_R ? FWS_U : FWS_INIT;
1067                                         } else {
1068                                                 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1069                                                 w->state = w->state>=FWS_C ? FWS_U : FWS_INIT;
1070                                         }
1071                                 }
1072                         }
1073                 }
1074                 read_unlock(&fib6_walker_lock);
1075
1076                 node_free(fn);
1077                 if (pn->fn_flags&RTN_RTINFO || FIB6_SUBTREE(pn))
1078                         return pn;
1079
1080                 rt6_release(pn->leaf);
1081                 pn->leaf = NULL;
1082                 fn = pn;
1083         }
1084 }
1085
1086 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
1087                            struct nl_info *info)
1088 {
1089         struct fib6_walker_t *w;
1090         struct rt6_info *rt = *rtp;
1091         struct net *net = info->nl_net;
1092
1093         RT6_TRACE("fib6_del_route\n");
1094
1095         /* Unlink it */
1096         *rtp = rt->u.dst.rt6_next;
1097         rt->rt6i_node = NULL;
1098         net->ipv6.rt6_stats->fib_rt_entries--;
1099         net->ipv6.rt6_stats->fib_discarded_routes++;
1100
1101         /* Reset round-robin state, if necessary */
1102         if (fn->rr_ptr == rt)
1103                 fn->rr_ptr = NULL;
1104
1105         /* Adjust walkers */
1106         read_lock(&fib6_walker_lock);
1107         FOR_WALKERS(w) {
1108                 if (w->state == FWS_C && w->leaf == rt) {
1109                         RT6_TRACE("walker %p adjusted by delroute\n", w);
1110                         w->leaf = rt->u.dst.rt6_next;
1111                         if (w->leaf == NULL)
1112                                 w->state = FWS_U;
1113                 }
1114         }
1115         read_unlock(&fib6_walker_lock);
1116
1117         rt->u.dst.rt6_next = NULL;
1118
1119         /* If it was last route, expunge its radix tree node */
1120         if (fn->leaf == NULL) {
1121                 fn->fn_flags &= ~RTN_RTINFO;
1122                 net->ipv6.rt6_stats->fib_route_nodes--;
1123                 fn = fib6_repair_tree(net, fn);
1124         }
1125
1126         if (atomic_read(&rt->rt6i_ref) != 1) {
1127                 /* This route is used as dummy address holder in some split
1128                  * nodes. It is not leaked, but it still holds other resources,
1129                  * which must be released in time. So, scan ascendant nodes
1130                  * and replace dummy references to this route with references
1131                  * to still alive ones.
1132                  */
1133                 while (fn) {
1134                         if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) {
1135                                 fn->leaf = fib6_find_prefix(net, fn);
1136                                 atomic_inc(&fn->leaf->rt6i_ref);
1137                                 rt6_release(rt);
1138                         }
1139                         fn = fn->parent;
1140                 }
1141                 /* No more references are possible at this point. */
1142                 BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
1143         }
1144
1145         inet6_rt_notify(RTM_DELROUTE, rt, info);
1146         rt6_release(rt);
1147 }
1148
1149 int fib6_del(struct rt6_info *rt, struct nl_info *info)
1150 {
1151         struct net *net = info->nl_net;
1152         struct fib6_node *fn = rt->rt6i_node;
1153         struct rt6_info **rtp;
1154
1155 #if RT6_DEBUG >= 2
1156         if (rt->u.dst.obsolete>0) {
1157                 BUG_TRAP(fn==NULL);
1158                 return -ENOENT;
1159         }
1160 #endif
1161         if (fn == NULL || rt == net->ipv6.ip6_null_entry)
1162                 return -ENOENT;
1163
1164         BUG_TRAP(fn->fn_flags&RTN_RTINFO);
1165
1166         if (!(rt->rt6i_flags&RTF_CACHE)) {
1167                 struct fib6_node *pn = fn;
1168 #ifdef CONFIG_IPV6_SUBTREES
1169                 /* clones of this route might be in another subtree */
1170                 if (rt->rt6i_src.plen) {
1171                         while (!(pn->fn_flags&RTN_ROOT))
1172                                 pn = pn->parent;
1173                         pn = pn->parent;
1174                 }
1175 #endif
1176                 fib6_prune_clones(info->nl_net, pn, rt);
1177         }
1178
1179         /*
1180          *      Walk the leaf entries looking for ourself
1181          */
1182
1183         for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->u.dst.rt6_next) {
1184                 if (*rtp == rt) {
1185                         fib6_del_route(fn, rtp, info);
1186                         return 0;
1187                 }
1188         }
1189         return -ENOENT;
1190 }
1191
1192 /*
1193  *      Tree traversal function.
1194  *
1195  *      Certainly, it is not interrupt safe.
1196  *      However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1197  *      It means, that we can modify tree during walking
1198  *      and use this function for garbage collection, clone pruning,
1199  *      cleaning tree when a device goes down etc. etc.
1200  *
1201  *      It guarantees that every node will be traversed,
1202  *      and that it will be traversed only once.
1203  *
1204  *      Callback function w->func may return:
1205  *      0 -> continue walking.
1206  *      positive value -> walking is suspended (used by tree dumps,
1207  *      and probably by gc, if it will be split to several slices)
1208  *      negative value -> terminate walking.
1209  *
1210  *      The function itself returns:
1211  *      0   -> walk is complete.
1212  *      >0  -> walk is incomplete (i.e. suspended)
1213  *      <0  -> walk is terminated by an error.
1214  */
1215
1216 static int fib6_walk_continue(struct fib6_walker_t *w)
1217 {
1218         struct fib6_node *fn, *pn;
1219
1220         for (;;) {
1221                 fn = w->node;
1222                 if (fn == NULL)
1223                         return 0;
1224
1225                 if (w->prune && fn != w->root &&
1226                     fn->fn_flags&RTN_RTINFO && w->state < FWS_C) {
1227                         w->state = FWS_C;
1228                         w->leaf = fn->leaf;
1229                 }
1230                 switch (w->state) {
1231 #ifdef CONFIG_IPV6_SUBTREES
1232                 case FWS_S:
1233                         if (FIB6_SUBTREE(fn)) {
1234                                 w->node = FIB6_SUBTREE(fn);
1235                                 continue;
1236                         }
1237                         w->state = FWS_L;
1238 #endif
1239                 case FWS_L:
1240                         if (fn->left) {
1241                                 w->node = fn->left;
1242                                 w->state = FWS_INIT;
1243                                 continue;
1244                         }
1245                         w->state = FWS_R;
1246                 case FWS_R:
1247                         if (fn->right) {
1248                                 w->node = fn->right;
1249                                 w->state = FWS_INIT;
1250                                 continue;
1251                         }
1252                         w->state = FWS_C;
1253                         w->leaf = fn->leaf;
1254                 case FWS_C:
1255                         if (w->leaf && fn->fn_flags&RTN_RTINFO) {
1256                                 int err = w->func(w);
1257                                 if (err)
1258                                         return err;
1259                                 continue;
1260                         }
1261                         w->state = FWS_U;
1262                 case FWS_U:
1263                         if (fn == w->root)
1264                                 return 0;
1265                         pn = fn->parent;
1266                         w->node = pn;
1267 #ifdef CONFIG_IPV6_SUBTREES
1268                         if (FIB6_SUBTREE(pn) == fn) {
1269                                 BUG_TRAP(fn->fn_flags&RTN_ROOT);
1270                                 w->state = FWS_L;
1271                                 continue;
1272                         }
1273 #endif
1274                         if (pn->left == fn) {
1275                                 w->state = FWS_R;
1276                                 continue;
1277                         }
1278                         if (pn->right == fn) {
1279                                 w->state = FWS_C;
1280                                 w->leaf = w->node->leaf;
1281                                 continue;
1282                         }
1283 #if RT6_DEBUG >= 2
1284                         BUG_TRAP(0);
1285 #endif
1286                 }
1287         }
1288 }
1289
1290 static int fib6_walk(struct fib6_walker_t *w)
1291 {
1292         int res;
1293
1294         w->state = FWS_INIT;
1295         w->node = w->root;
1296
1297         fib6_walker_link(w);
1298         res = fib6_walk_continue(w);
1299         if (res <= 0)
1300                 fib6_walker_unlink(w);
1301         return res;
1302 }
1303
1304 static int fib6_clean_node(struct fib6_walker_t *w)
1305 {
1306         int res;
1307         struct rt6_info *rt;
1308         struct fib6_cleaner_t *c = container_of(w, struct fib6_cleaner_t, w);
1309         struct nl_info info = {
1310                 .nl_net = c->net,
1311         };
1312
1313         for (rt = w->leaf; rt; rt = rt->u.dst.rt6_next) {
1314                 res = c->func(rt, c->arg);
1315                 if (res < 0) {
1316                         w->leaf = rt;
1317                         res = fib6_del(rt, &info);
1318                         if (res) {
1319 #if RT6_DEBUG >= 2
1320                                 printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res);
1321 #endif
1322                                 continue;
1323                         }
1324                         return 0;
1325                 }
1326                 BUG_TRAP(res==0);
1327         }
1328         w->leaf = rt;
1329         return 0;
1330 }
1331
1332 /*
1333  *      Convenient frontend to tree walker.
1334  *
1335  *      func is called on each route.
1336  *              It may return -1 -> delete this route.
1337  *                            0  -> continue walking
1338  *
1339  *      prune==1 -> only immediate children of node (certainly,
1340  *      ignoring pure split nodes) will be scanned.
1341  */
1342
1343 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1344                             int (*func)(struct rt6_info *, void *arg),
1345                             int prune, void *arg)
1346 {
1347         struct fib6_cleaner_t c;
1348
1349         c.w.root = root;
1350         c.w.func = fib6_clean_node;
1351         c.w.prune = prune;
1352         c.func = func;
1353         c.arg = arg;
1354         c.net = net;
1355
1356         fib6_walk(&c.w);
1357 }
1358
1359 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
1360                     int prune, void *arg)
1361 {
1362         struct fib6_table *table;
1363         struct hlist_node *node;
1364         struct hlist_head *head;
1365         unsigned int h;
1366
1367         rcu_read_lock();
1368         for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
1369                 head = &net->ipv6.fib_table_hash[h];
1370                 hlist_for_each_entry_rcu(table, node, head, tb6_hlist) {
1371                         write_lock_bh(&table->tb6_lock);
1372                         fib6_clean_tree(net, &table->tb6_root,
1373                                         func, prune, arg);
1374                         write_unlock_bh(&table->tb6_lock);
1375                 }
1376         }
1377         rcu_read_unlock();
1378 }
1379
1380 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1381 {
1382         if (rt->rt6i_flags & RTF_CACHE) {
1383                 RT6_TRACE("pruning clone %p\n", rt);
1384                 return -1;
1385         }
1386
1387         return 0;
1388 }
1389
1390 static void fib6_prune_clones(struct net *net, struct fib6_node *fn,
1391                               struct rt6_info *rt)
1392 {
1393         fib6_clean_tree(net, fn, fib6_prune_clone, 1, rt);
1394 }
1395
1396 /*
1397  *      Garbage collection
1398  */
1399
1400 static struct fib6_gc_args
1401 {
1402         int                     timeout;
1403         int                     more;
1404 } gc_args;
1405
1406 static int fib6_age(struct rt6_info *rt, void *arg)
1407 {
1408         unsigned long now = jiffies;
1409
1410         /*
1411          *      check addrconf expiration here.
1412          *      Routes are expired even if they are in use.
1413          *
1414          *      Also age clones. Note, that clones are aged out
1415          *      only if they are not in use now.
1416          */
1417
1418         if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) {
1419                 if (time_after(now, rt->rt6i_expires)) {
1420                         RT6_TRACE("expiring %p\n", rt);
1421                         return -1;
1422                 }
1423                 gc_args.more++;
1424         } else if (rt->rt6i_flags & RTF_CACHE) {
1425                 if (atomic_read(&rt->u.dst.__refcnt) == 0 &&
1426                     time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) {
1427                         RT6_TRACE("aging clone %p\n", rt);
1428                         return -1;
1429                 } else if ((rt->rt6i_flags & RTF_GATEWAY) &&
1430                            (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) {
1431                         RT6_TRACE("purging route %p via non-router but gateway\n",
1432                                   rt);
1433                         return -1;
1434                 }
1435                 gc_args.more++;
1436         }
1437
1438         return 0;
1439 }
1440
1441 static DEFINE_SPINLOCK(fib6_gc_lock);
1442
1443 void fib6_run_gc(unsigned long expires, struct net *net)
1444 {
1445         if (expires != ~0UL) {
1446                 spin_lock_bh(&fib6_gc_lock);
1447                 gc_args.timeout = expires ? (int)expires :
1448                         net->ipv6.sysctl.ip6_rt_gc_interval;
1449         } else {
1450                 if (!spin_trylock_bh(&fib6_gc_lock)) {
1451                         mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
1452                         return;
1453                 }
1454                 gc_args.timeout = net->ipv6.sysctl.ip6_rt_gc_interval;
1455         }
1456
1457         gc_args.more = icmp6_dst_gc();
1458
1459         fib6_clean_all(net, fib6_age, 0, NULL);
1460
1461         if (gc_args.more)
1462                 mod_timer(&net->ipv6.ip6_fib_timer,
1463                           round_jiffies(jiffies
1464                                         + net->ipv6.sysctl.ip6_rt_gc_interval));
1465         else
1466                 del_timer(&net->ipv6.ip6_fib_timer);
1467         spin_unlock_bh(&fib6_gc_lock);
1468 }
1469
1470 static void fib6_gc_timer_cb(unsigned long arg)
1471 {
1472         fib6_run_gc(0, (struct net *)arg);
1473 }
1474
1475 static int fib6_net_init(struct net *net)
1476 {
1477         setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
1478
1479         net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
1480         if (!net->ipv6.rt6_stats)
1481                 goto out_timer;
1482
1483         net->ipv6.fib_table_hash = kcalloc(FIB_TABLE_HASHSZ,
1484                                            sizeof(*net->ipv6.fib_table_hash),
1485                                            GFP_KERNEL);
1486         if (!net->ipv6.fib_table_hash)
1487                 goto out_rt6_stats;
1488
1489         net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
1490                                           GFP_KERNEL);
1491         if (!net->ipv6.fib6_main_tbl)
1492                 goto out_fib_table_hash;
1493
1494         net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
1495         net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1496         net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
1497                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1498
1499 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1500         net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
1501                                            GFP_KERNEL);
1502         if (!net->ipv6.fib6_local_tbl)
1503                 goto out_fib6_main_tbl;
1504         net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
1505         net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
1506         net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
1507                 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
1508 #endif
1509         fib6_tables_init(net);
1510
1511         return 0;
1512
1513 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1514 out_fib6_main_tbl:
1515         kfree(net->ipv6.fib6_main_tbl);
1516 #endif
1517 out_fib_table_hash:
1518         kfree(net->ipv6.fib_table_hash);
1519 out_rt6_stats:
1520         kfree(net->ipv6.rt6_stats);
1521 out_timer:
1522         return -ENOMEM;
1523  }
1524
1525 static void fib6_net_exit(struct net *net)
1526 {
1527         rt6_ifdown(net, NULL);
1528         del_timer_sync(&net->ipv6.ip6_fib_timer);
1529
1530 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
1531         kfree(net->ipv6.fib6_local_tbl);
1532 #endif
1533         kfree(net->ipv6.fib6_main_tbl);
1534         kfree(net->ipv6.fib_table_hash);
1535         kfree(net->ipv6.rt6_stats);
1536 }
1537
1538 static struct pernet_operations fib6_net_ops = {
1539         .init = fib6_net_init,
1540         .exit = fib6_net_exit,
1541 };
1542
1543 int __init fib6_init(void)
1544 {
1545         int ret = -ENOMEM;
1546
1547         fib6_node_kmem = kmem_cache_create("fib6_nodes",
1548                                            sizeof(struct fib6_node),
1549                                            0, SLAB_HWCACHE_ALIGN,
1550                                            NULL);
1551         if (!fib6_node_kmem)
1552                 goto out;
1553
1554         ret = register_pernet_subsys(&fib6_net_ops);
1555         if (ret)
1556                 goto out_kmem_cache_create;
1557
1558         ret = __rtnl_register(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib);
1559         if (ret)
1560                 goto out_unregister_subsys;
1561 out:
1562         return ret;
1563
1564 out_unregister_subsys:
1565         unregister_pernet_subsys(&fib6_net_ops);
1566 out_kmem_cache_create:
1567         kmem_cache_destroy(fib6_node_kmem);
1568         goto out;
1569 }
1570
1571 void fib6_gc_cleanup(void)
1572 {
1573         unregister_pernet_subsys(&fib6_net_ops);
1574         kmem_cache_destroy(fib6_node_kmem);
1575 }